Detonator or auxiliary protective alarm spark-gap for high-frequency apparatus.



No. 785,671. PATENTED MAR. 21, 1905.

H. JACKSON. DETONATOR OR UXILIARY PROTECTIVE ALARM SBARK GAP FOR HIGH FREQUENCY APPARATUS.

APPLICATION FILED JULY 27, 1904.

f a A/ l l lnvtzrrrcn Wwnaaaas A mi. H i Ju UNITED STATES Patented March 21, 1905.

PATENT OFFICE;

HOWARD JACKSON, OF NEWTON, MASSACHUSETTS.

SPECIFICATION forming part of Letters Patent No. 785,671, dated March 21, 1905.

Application filed July 27, 1904. Serial No. 218,438.

To all whom it may concern.-

Be it known that 1, HOWARD J AoKsoN, a citizen of the United States, and a resident of Newton, h Iassacl1usetts,l1ave invented an Improvement in Detonators or Auxiliary Protective Alarm Spark-Gaps for High-Frequency Apparatus, of which the following description, in connection with the accompanying drawings, is a specification, like letters on thedrawings representing like parts.

The increased efficiency of high-frequency apparatus of the kind employed in connection with X-ray work, therapeutical work, and the like has occasioned the placing in the hands of novices and the unskilled of apparatuses more or less complex and requiring heavy and dangerous currents; and the present invention has for its object the provision of protecting mechanism for the apparatus in the form of means for automatically notifying the user of such apparatus in case anything goes wrong.

My invention includes in its preferred embodiment means for promptly notifying the user both by sound and sight and also by the sense of smell whenever an open circuit or other breakdown occurs.

The constructional details of my invention and the operation thereof and further resulting advantages will appear more fully in the course of the following description, reference being had to the accompanying drawings, in which I have illustrated one embodiment of my invention.

In the drawings, Figure 1 is a fragmentary view of a cabinet, showing my invention applied thereto. Fig. 2 is an enlarged front elevation thereof. Fig. 3 is a cross-sectional view taken on the line 3 3, Fig. 2. Fig. 4 is a diagrammatical View showing the circuit connections In many ways a breakdown is liable to occur in the use of the kind of apparatus in question as,for example, if the spark-gap be improperly connected or accidentally omitted (as it often is for removal in cleaning or renewing) and the current is turned on the back discharge from the condenser will break down the insulation of the transformer-or the conductors from the condenser to the induction-coil or step-up transformer may become detached or imperfectly attached, in which case the whole output is thrown into the condenser and not having any other path to discharge excepting through the transformer immediately punctures the insulation thereof, as before. Accordingly I have provided an auxiliary device in the form of a spark-gap permanently in circuit and so situated as to be plainly visible at all times, being preferably on the outside of the box or case in which the apparatus is situated and also preferably containing means for giving off an offensive or pungent odor when heated, said auxiliary spark-gap being so adjusted as to be inoperative when the main circuit is working normall y, but becoming operative instantly when the main circuit operates abnormally.

My invention is capable of a wide variety of embodiments, the form herein shown, however, being preferred because of its neat appearance, compact arrangement, and certainty and efficiency of action.

Referring to Fig. 4, I have indicated a transformer 60, connected by wires 6 c to an induction-coil (Z, 'a Kinraide coil being shown for convenience, (see Patent No. 615,653, December 6, 1898,) operated in connection with a spark-gap c and a condenser f in the usual manner. I introduce across the circuit an auxiliary spark-gap or detonator 9, being herein shown as between the transformer a and the condenser f, although it is obvious that it may be on the other side thereof or otherwise located, provided it is connected around the part or parts which are liable to cause the trouble. The constructional details of the preferred embodiment of this auxiliary spark-gap or detonator are shown best in Figs. 2 and 3, where it will be seen that the box or cabinet h is cut away at h to provide a free and unrestricted opening to the interior, and over this opening ltl secure a heavy insulating-block g, of porcelain, glass, or othersuitable non-inflammable material, on which are mounted opposite electrodes or discharge-buttons 9 shown as retained by screws g", which also serve to retain protectors g of hard rubber or other insulating and odoriferone material. Binding-posts g connect the wires 5 c at their inner ends and engage the electrodes 7 as far apart as possible to prevent any danger of sparking across on the inside of the box. To make a distinctive and very loud noise and also to prevent any preliminary brush discharges, which might cause a sudden discharge, tending to annoy and interfere with the steadiness of the main apparatus, I make the electrodes 7 circular in form, with rounded edges. This permits the electrodes to be brought almost as close' together as the plates of the main spark-gap, without any tendency, however, to operate during the normal operation of the apparatus. The protectors are the same shape as the electrodes and overhang the latter, so as to prevent the operator from accidentally coming in contact with said electrodes, and yet leave the latter suiiiciently exposed to permit the free circulation of air and to permit the arc to be visible whenever the detonator is called into action. The electrodes y" are adjusted apartsufiiciently to provide a slightly greater resistance than that of the coil (Z and spark-gap (a, which carry the oscillating current from the condenser, the adjustment of the device determining the amount of strain that can be thrown upon the apparatus. amount of strain will usually be greater or less, according to the character of the insulation of the trai'isformer a. The latter is one of the most expensive portions of such an apparatus, and hence it is desirable to protect it in any event, and therefore the electrodes g are usually adjusted from each other such a distance as to give prompt notice of any back discharge from the condenser or other similar danger liable to break down the insulation of the transformer.

In use if the apparatus is in proper condition, with all the parts properly adjusted and connected, the current passes in usual manner from the transformer a by the conductors 7) c to the condenser, whose discharges are passed through the coil (Z by the action of the sparkcap (2. If new anything should occur to increase the resistance of the circuit or cause a breakdown therein, the current will immediately set the detonator g in operation, preferring this path of relatively low resistance to overcoming the impedance of the transformer, causing a loud and startling noise because of the discharge between the electrodes g and as the device 7 is in plain sight the blinding light therefrom will also attract attention, and simultaneously therewith the smoking of the rubber protectors y" will compel attention by the sense of smell. 'lhereuponthe operator instantly shuts off the current and is then at liberty to investigate at his leisure the cause of the trouble.

It will be evident that the apparatus may be guarded with any degree of nicety desired, according to the distance apart of the electrodes The auxiliary spark-gap or detonator remains idle orinactive at all times during This the proper running of the apparatus to which it is applied, but is ever present and effective for warning the operator of any dangerous tendency of the condenser-current to flow back to the transformer. It does not depend in any way upon any special winding or contain any spring-actuated device or other movable parts; but it consists simply of a sparkgap not requiring any skill or understanding or attention on the part of the operator.

As already intimated, I am aware that many changes in form, arrangement, and combination of parts may be resorted to without departing from the spirit and scope of my invention.

Having fully described my invention, what I claim, and desire to secure by Letters Patent of the United States, is

1. An apparatus of the kind described, comprising an electric circuit, a cabinet, containing means for impressing thereon a high-frequency current, and a translating device, and means mounted on said cabinet in open view for giving instant visual warning upon the flow of destructive abnormal current, said means being protected from accidental contact.

2. A high-frequency cabinet for therapeutical work and. the like, containing circuit-wires leading from a suitable source of current, a high-freq uency high-potential disruptive discharge mechanism within said cabinet to operate in connection with said circuit, and an auxiliary detonator in parallel with said mechanism at the high-frequency high-potential end of said circuit, for giving instant audible warning upon the flow of destructive abnormal current.

3. A high-frequency cabinet for therapeutical work and the like, containing circuit-wires leading from a suitable source of current, a high-frequency high-potential disruptive-discharge mechanism within said cabinet to operate in connection with said circuit, and means responsive to the flow of destructive abnormal current for generating instantly a volume of bad-smelling gas or smoke capable of immedi ately permeating the atmosphere to the distance usually occupied by the operator, for giving warning to said operator by the sense of smell, said gas-generating means being mounted in an exposed position on said cabinet whence the said gas can freely escape in large volumes for the purpose set forth.

4:. A high-frequency device for therapeutical work and the like, comprising a cabinet, containing a transformer, a condenser, a sparkgap device, and a translating device, and an electric circuit connecting said apparatus for producing a high frequency high potential disruptive discharge, and an auxiliary sparkgap device mounted on the outside of said cabinet and connected across said circuit between said transformer and said translating device, said auxiliary device being normally inactive but'capable of instant operation upon the flow of abnormal current for giving Warning to the operator for preventing damage to the transformer.

5. A case containing electrical apparatus and having an aperture therethrough, a noninflammable insulating-plate secured thereto, a spark-gap device mounted on said plate, and overhanging protecting means for said sparkgap.

6. A spark-gap device, comprising a support of non-inflammable insulating material, opposite electrodes mounted flat against the top surface thereof, and overhanging protectors mounted directly on said electrodes for preventing accidental contact therewith while leaving the spark-gap exposed and visible.

opposite electrodes mounted thereon, and protectors mounted on said electrodes projecting over the discharge-gap, said protectors being composed of odoriferous material becoming active in the presence of the arc from said electrodes.

8. A spark-gap device, having separated electrodes provided adjacent their discharge ends with material capable of emitting an odoriferous smoke when heated by the discharge, for giving Warning to the operator.

In testimony whereof I have signed my name to this specification in the presence of two subscribing Witnesses.

HOWARD JACKSON.

Witnesses:

GEO. H. MAXWELL, EMILIO A. CARDARELLO. 

